BIO1022 Study Guide - Final Guide: T-Tubule, Insect Flight, Bivalvia
Document Summary
Striated muscle: e. g. bivalve valve closure muscle. Striated muscle: many nuclei, transverse tubules. Involved in pumping of heart to push blood around the body. Force affected by: type of lever (joint, type of fibre (slow or fast twitch, muscle cross-sectional area. Mechanical advantage determined by relative position of fulcrum: low mechanical advantage= low power but high speed e. g. bicep, high mechanical advantage= high power but low speed e. g. jaw. Muscle cells consist of many myofibrils, which are composed of sarcomeres. Sarcomeres are the functional units in the geometric pattern of actin and myosin filaments. Bundles of muscle fibres make up muscles. Actin and myosin are in an interlocking pattern. Actin are the thin filaments, myosin are thick filaments (cid:858)slidi(cid:374)g fila(cid:373)e(cid:374)t (cid:373)odel(cid:859): Fibres pull apart, and contract together to contract and relax. Myosin heads hydrolyse atp in order to bind to the actin strand, forming a cross- bridges. This moves the actin filament along, to contract.
